Corrupt files in Appointment+ Version 1.9.4

In the /includes/addon directory all files appear as they were 200-300 bytes long.
This is evidently not the case.
Opening the files with all my editors I can get only the initial few lines (the initial comment) and nothing else. Many of them gives me an error while trying to open the file.
What's strange is that the php works correctly, but cannot just be edited and appear very small.
I don't know what's happened to them, but please post a fix asap, as I need to edit a couple of them

Kind regards